Heel hold-down device for ski boot

ABSTRACT

This heel hold-down device for resiliently and releasably retaining the heel of a ski boot in a position of engagement with the ski surface comprises a resilient mechanism housed within the base member of the device and comprising a coil compression spring acting upon a transverse rotary shaft carrying at either ends eccentric trunnions engaging cam elements provided on said pivoting jaw or on the supporting bracket thereof, the contour of said cam elements being such that when said shaft is locked in its operative position by said spring said gripping jaw is also retained in its normal, lower position, the upward movement of said jaw causing the rotation of said transverse rotary shaft about its axis against the resistance of the spring. Said cam element may consist of apertures formed in a pair of flanges extending on either side of said base member and each formed with a cam-forming aperture engaged by an eccentric trunnion carried by the corresponding end of the rotary shaft. A control lever is secured to said bracket or to said shaft to permit a quick release of the heel.

United States Patent 1 Beyl 1 Apr. 3, 1973 [54] HEEL HOLD-DOWN DEVICE FOR SKI BOOT [76] Inventor: Jean Joseph Alfred Beyl, 202 Boulevard Victor Hugo, Nevers, France [22] Filed: Mar. 2, 1971 v 21 Appl. No.: 120,236

[30] Foreign Application Priority Data Primary Examiner-Leo Friaglia Assistant Examiner-Robert R. Song Attorney-Harry C. Bierman, Jordan B. Bierman and Bierman & Bierman [57] ABSTRACT This heel hold-down device for resiliently and releasably retaining the heel of a ski boot in a position ofengagement with the ski surface comprises a resilient mechanism housed within the base member of the device and comprising a coil compression spring acting upon a transverse rotary shaft carrying at either ends eccentric trunnions engaging cam elements provided on said pivoting jaw or on the supporting bracket thereof, the contour of said cam elements being such that when said shaft is locked in its operative position by said spring said gripping jaw is also retained in its normal, lower position, the upward movement of said jaw causing the rotation of said transverse rotary shaft about its axis against the resistance of the spring.

Said cam element may consist of apertures formed in a pair of flanges extending on either side of said base member and each formed with a cam-forming aperture engaged by an eccentric trunnion carried by the corresponding end of the rotary shaft. A control lever is secured to said bracket or to said shaft to permit a quick release of the heel.

7 Claims, 15 Drawing Figures PATENTEUMR 3 I975 SHEET 1 OF 7 9 NE E v i:\ H.

PATENTEDAPRB I975 SHEET 2 OF 7 21 III E 1. Am

N @m N PATENTEDAPRB I275 SHEET LL 0F 7 HEEL HOLD-DOWN DEVICE FOR SKI BOOT The present invention relates to hold-down devices adapted to bind the heel of a ski boot to a ski and to automatically release the boot in case of forward fall of the skier.

Releasable heel hold-down devices of this character comprise as a rule a heel gripping jaw pivotally mounted to a fixed base but retained in its normal position by a resilient mechanism housed within said base. A number of different mechanisms have already been proposed to this end. Some of these known devices are so arranged that they constantly urge the gripping jaw resiliently to its normal position to avoid an undesired or untimely release of the heel in case of stretching efforts not requiring a complete release of the ski boot.

More particularly, this invention relates to holddown devices of the type broadly set forth hereinabove but wherein the force of the spring of the resilient return mechanism acts against a rotary shaft mounted in a transverse horizontal position in the base, this jaw being coupled in turn to the heel gripping jaw or more exactly with the bracket supporting this jaw.

A heel hold-down device of this character has already been disclosed in the US. Pat. application Ser. No. 808,122 filed on Mar. 18, 1969 in the name of applicant.

In this prior device the transverse rotary shaft of the return mechanism and the gripping jaw supporting bracket are interconnected by means of a cam-forming pivoting member acting upon a transverse pin carried by said bracket. On the other hand, this pivoting member is also adapted to act as a control lever for raising at will the retaining jaw when it is desired to release the heel of the boot from the ski.

It is the essential object of the present invention to provide a heel hold-down device of the samegeneral type as described hereinabove but designed with a view to simplify considerably. the coupling between the rotary shaft of the resilient mechanism and the retaining jaw supporting bracket. This device is also arranged with a view to enable the return spring to act upon said rotary transverse shaft either directly as in the abovementioned patent application or indirectly through any suitable intermediate member. Moreover, this holddown device comprises a number of improvements in comparison with hitherto known devices of the same character.

To this end, the heel hold-down device according to the present invention is characterized essentially in that the pivoting jaw and the shaft of the retaining mechanism are interconnected through a stud or like member secured in an eccentric position to at least one end of said shaft and adapted to engage a cam provided either. on said pivoting jaw or on the jaw supporting bracket, the contour of said cam being such that in the position causing said rotary shaft to be held against motion by said spring the pivoting jaw is held in its normal, lower position, the upward movement of this jaw being attended by the rotation of said shaft about its axis against the resistance of said spring co-acting therewith. According to an advantageous form of embodiment, the cam or cams provided on said pivoting jaw or on the support thereof have a curved contour such that the pivotal movement of said jaw in one direction tends torotate the shaft of the retaining mechanism in the opposite direction, and vice versa, and furthermore this shaft is rigid with a control lever secured thereto in such angular position that it extends substantially horizontally to the rear in the normal position of the device, that is, when the jaw thereof is in its lower or operative position.

Under these conditions, it is only necessary to pivot this lever in the forward direction for causing the upward movement of the jaw and release the heel of the ski boot.

However, other features and advantages of this device will appear as the following description proceeds with reference to the attached drawings illustrating diagrammatically by way of example a few typical forms of embodiment of this invention. In the drawings FIG. l-is a side elevational view with parts broken away, showing a heel hold-down device according to this invention FIG. 2 is a plan view from above of the same device FIG. 3 is a longitudinal section taken along the line IIIIII of FIG. 2

FIG. 4 is a cross section taken along the line lV-IV of FIG. 3

FIG. 5 is a side elevational view similar to FIG. 1 but showing the same heel hold-down device during the upward or release movement of the heel gripping jaw FIGS. 6 and 7 are diagrams illustrating the mode of operation of the resilient retaining mechanism co-acting with the support bracket of theheel gripping jaw FIG. 8 is a perspective view showing the rotary shaft of the resilient retaining mechanism FIG. 9 is a side elevational view showing another form of embodiment of the heel hold-down device ol this invention;

FIG. I0 is -a longitudinal section showing details of this modified form of embodiment FIG. 1 1 is a cross section taken alont the line XI-XI of FIG. 10

FIG. 12 is a cross sectional view showing another modified form of embodiment of the heel hold-down device of this invention;

FIG. 13 is a longitudinal section taken along the line XIII-XIII of FIG. 12;

FIGS. 14 and 15 are elevational views showing twoother forms of embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The releasable heel hold-down device illustrated in FIGS. 1 to 8 inclusive comprises essentially a jaw 1 adapted to grip the heel of a ski boot C to be held down on the upper surface of a ski C. This jaw is carried by a strap-like support or bracket 2 pivotally mounted to a base member 3 secured permanently to the aforesaid upper surface of the ski S, at the rear of the position normally occupied by the heel on the ski.

To this end the base member 3 may be secured in turn, for example by means of pins or rivets 4, to a pair of lateral bearing angle members 5 secured by means of screws 6 to the top of the ski S.

However, these two angle members may also be so mounted as to permit their sliding movement in the 1ongitudinal direction in corresponding slideways formed in a base plate secured to the ski, adequate means being also provided in this case for locking the base member or the hold-down device in the desired longitudinal position.

The jaw supporting bracket 2 comprises rear extensions in the form of a pair of vertical arms or flanges 7 disposed on either side of the lateral faces of base member 3. These arms or flanges are pivoted to the outer ends of a horizontal transverse pin 8 carried by the upper and front portion of base member 3 (FIG. 1

As already explained in the foregoing, the resilient mechanism provided for retaining the jaw l or more particularly its supporting bracket 2 is of the same type as that contemplated in the heel hold-down device disclosed and illustrated in the US. Pat. application Ser. No. 808,112 filed on Mar. 18,1969.

In fact, this mechanism comprises a rotary shaft 9 responsive to the pressure exerted by a coil compression spring 10. More particularly, this shaft 9 has formed thereon a flat face 11 normally inclined in a rearward and downward direction and engaged by a piston 12 responsive to said spring 10. The rotary shaft 9 extends horizontally and is rotatably mounted about its axis in a bore formed transversely in the base member 3 below the fulcrum pin 8 to which the jaw supporting bracket is pivotally mounted.

The coil compression spring as well as the piston 12 and the piston rod 13 are enclosed in a cavity 14 formed in the base member 3. This cavity is closed at its rear, end by a screw plug 15 whereby the force of spring 10 may be pressed to the desired value.

Due to the provision of said flat face 11, the shaft 9 comprises two edges 16a, 16b parallel to its generatrices and disposed symmetrically on either side of its center line. Thus, in case of rotation of said shaft 9 in the direction of the arrow F,, the piston 12 will exert a pressure against the upper edge 16a, thus creating an elastic return torque urging the rotary shaft 9 to its normal position in which the flat face 11 is parallel to, and in complete engagement, with the registering face of piston 12.

The two ends of rotary shaft 9 are flush to the lateral faces of base number 3. However, each end face forward aforesaid carries a projecting trunnion 17 provided with a small, loosely rotating roller 18. Each trunnion engages an elongated aperture 19 formed in the registering lateral arm or flange constituting the rear extension of the bracket 2 supporting the gripping jaw 1. Thus, these trunnions 17 will provide a mechanical coupling between the rotary shaft 9 of the mechanism and the bracket 2. The elongated apertures 19 formed in the lateral arms 7 of bracket 2 act as cam elements to ensure the necessary control engagement between this bracket ,and the resilient retaining mechanism. The contour of these cam elements is such that in the normal holding position of shaft 9 as illustrated in FIG. 3 the gripping jaw 1 is held in its lower or operative position so as to hold down the heel of the ski boot. However, this cam contour is so designed that any upward movement of the jaw, for example to the position shown in FIG. 5, causes the rotation of shaft 9 about its axis in the direction of the arrow F against the resistance of spring 10. During this movement the trunnions 17 can slide in the elongated apertures 19 of the pair of lateral flanges or arms of support 2.

In order to facilitate the manufacture, the trunnions 17 may consist for example of the opposite ends of a single pin 20 extending through the rotary shaft 9 and emerging from the ends thereof. In this respect it may be noted that the position of these two trunnions at the ends of shaft 9 is eccentric in relation thereto. The jaw raising movement may be controlled voluntarily by means of a control lever 22 rigid with the jaw supporting bracket 2. v

In its normal position this lever 22 extends upwards behind the boot C as illustrated in FIG. 1. When the user wishes to release the boot heel for removing the boot from the ski, it is only necessary to grip and pivot said lever 22 manually to the rear (or in the clockwise direction as seen in FIG. 1) as shown by the arrow F in FIG. 5. Of course, this upward movement of bracket 2 is attended by a rotation of the rotary shaft 9 of the return mechanism in the same direction.

When a stretching effort is exerted on the skiers leg, this will urge the jaw supporting bracket 2 upwards against the elastic resistance of the resilient return mechanism. Under these conditions the operation of the heel hold-down device of this invention takes place as follows 1. As long as the rotary shaft 9 has not attained the endmost position shown in FIG. 7, the pressure exerted by the piston 12 against the edge 16a of flat face 11 of shaft 9 tends to restore the latter to its initial position. This is shown in the example of FIG. 6.

In this position, the shaft 9 has pivoted about its axis 0 by an angle a which may be relatively wide, since a value of about 50 may then be attained.

The pressure exerted by piston 12 subsequently tends to restore the shaft 9 to its normal position, but during this return movement the shaft 9 carries along the bracket 2 by pivoting same about its pivot pin 8 as a consequence of the pressure exerted by the trunnions 17 and rollers 18 against the lower edge of the aforesaid elongated apertures 19.

Under these conditions, if a stretching effort is exerted on the skiers leg the heel of boot C is allowed to rise momentarily, thus preventing any risk of accident such as the tearing of the Achilles tendon which would become possible if the boot heel were rigidly held against the ski.

However, after this upward movement of the heel, the boot C is restored automatically, to its ski-engaging position due to the action of the resilient return mechanism.

2. Nevertheless, if the stretching effort exerted on the leg is relatively important, the jaw 1 can attain the end position shown in FIG. 5 in which the heel is released completely.

In this case the rotary shaft 9 is also brought to its endmost position .illustrated in FIG. 7, wherein the angle B of its pivotal movement is such that the pressure exerted by the piston 12 against the edge 16a of shaft 9 cannot produce any elastic return torque. Much to the contrary, the pressure exerted by piston 12 tends to keep the shaft 9 in its corresponding position. Thus, the gripping jaw l itself is held in its upper position.

However, the boot heel can be locked again in its normal position by simply re-engaging the heel into the jaw 1 and depressing the locking control treadle2l carried by said bracket 2 (see FIG. 2).

With this arrangement, the device of this invention affords a relatively long release stroke before fully releasing the heel in case a stretching effort were exerted on the leg. In fact, as long as the shaft 9 of the resilient retaining mechanism has not attained its maximum angular position illustrated in FIGS. 5 and 7, the pressure exerted by piston 12 tends to restore the jaw 1 to its normal position and hold the heel of boot C in its initial position. Now practical tests performed in this field proved that the possibility of a relatively long prerelease stroke before the complete release of the boot constitutes an essential requirement of a satisfactory safety ski binding.

Of course, the arrangement of lever 22 for voluntarily controlling the release of the boot heel could differ from the one illustrated. Besides, this lever could be replaced by any other member or system adapted to control the upward movement of the jaw supporting bracket 2.

FIGS. 9 to 11 of the drawings illustrate a different form of embodiment of the heel hold-down device of this invention, wherein the release control lever is independent of the bracket supporting the retaining jaw.

Except for this difference, this modified heel holddown device displays the same characteristic features as the preceding form of embodiment. Besides, the different parts having the same function as those of the preceding form of embodiment are designated by the same reference numerals, plus the index a.

In this modified form of embodiment, the boot release lever 22a is rigid with the rotary shaft 9a of the retaining mechanism in lieu of the jaw supporting bracket, and the connecting means provided between this shaft 9a and the bracket 2a are such that these two members are caused to revolve in opposite direction. Under these conditions, lifting the control lever 22a in the forward direction permits of raising the gripping jaw la by causing the latter to pivot backwards.

This lever 22a is substantially fork-shaped and its two branches extending on either side of base member 3a are rotatably solid with shaft 9a, due to the provision of a pair of parallel. transverse pins 17a, 17b extending throughout the length of this shaft. These two pins 17a, 17b are eccentric in relation to the axis 0 of shaft 9a, and one of them, namely pin 17a, extends beyond the two lateral branches of lever 22a. In fact the two projecting ends of this pin v17a are adapted to act as trunnions for controlling the pivotal movements of bracket 2a of retaining jaw la during the upward movement of lever 22a.

Each trunnion carries a small roller 18a engaging an arcuate slot 19a formed in the corresponding lateral arm or flange of the bracket 2a supporting the retaining or gripping jaw. These slots 19a constitute cam means ensuring the necessary coupling between the retaining mechanism and the grippingjaw.

In this respect it may be noted that the shape of these apertures 19a differs from that of the preceding form of embodiment. In fact, these apertures 19a are arcuate and their contour is such that then the bracket 2a is pivoted in the jaw-raising direction the shaft 9a is rotated in the opposite direction, and vice versa.

The control lever 22a is secured to the shaft 9a in such angular relationship that in its inoperative position this lever extends substantially horizontally to the rear,

as illustrated in thick lines in FIG. 9. Thus, this lever is somewhat retracted and any increment in the over-all dimensions of the device is safely avoided.

With this arrangement the rotary shaft 9a responsive to the force of spring 10a tends through the medium of trunnions 17a engaging the arcuate apertures 19a of supporting bracket 2a to hold this bracket and therefore the gripping jaw 1a in their normal, lower position.

When an abnormal stretching effort is applied to the skiers leg the heel of boot C tends to move upwards and to carry along concomittantly the jaw la and its supporting bracket 2a.

Of course, this movement takes place against the elastic resistance produced by the retaining mechanism. If the stretching effort is important and prolonged, the jaw 1a will attain the extreme or uppermost position 1c shown in dash and dot lines in FIG. 9. Thus the control lever 22a is also raised to a position 22b also shown in dash and dot lines.

With the above-described arrangement it is thus possible to raise voluntarily the gripping jaw 1a for releasing the heel of boot C, for example at the end of a ski run, by pulling the control lever 22a upwards or pivoting same in the direction of the arrow F (FIG. 9). Now this movement can easily be performedby pulling a traction strap 23 attached to the free or outer end of lever 22a.

Preferably, this strap 12 may consists of the safety belt usually provided for keeping'the ski tied to the skiers leg in case of release of either of the ski bindings provided at the toe and heel ends of the corresponding boot.

Under these conditions, the user can effect this maneuver without difficulty and without having to bend down. In fact, when the lever 22a is lifted in the direction of the arrow F this movement is attended by a rotational movement of transverse shaft 9a about its axis 0 in the same direction. Now during this movement the control trunnions 17a are caused to travel in the cam-forming arcuate slots 19a of lateral flanges or arms 7a of the bracket 2a supporting the gripping jaw la.

Due to the shape of these apertures 19a this movement causes the bracket 2a to pivot upwards about the pin 8a, in the direction of the arrow F (FIG. .9). Preferably, a spring 24 (FIG. 10) disposed around the pin 8a urges the bracket 2a in this direction.

The jaw 10 is reset in its operative position by simply exerting a pressure with the heel on the treadle 21a provided to this end. This movement is attended by the pivotal movement of jaw la and bracket 2a about the pin 8a in the direction of the arrow F The cam-forming curved slots 19a then carry along the trunnions 17a to rotate the shaft 9a about its axis 0 in the opposite direction, i.e., in a direction opposed to that shown by the arrow F,.

Of course, this rotational movement is attended by a pivotal movement of control lever 22a in the same direction, until this lever has resumed its normal or inoperative position shown in thick lines in FIG. 9, in which said lever extends substantially horizontally.

From the foregoing it will readily appear to those conversant with the art that this modified heel holddown device is attended by a number of advantageous features in comparison with the form of embodiment ilthe easy operation of this device when it is desired to voluntarily release the heel, for example by raising the retaining jaw at the end of a ski run.

However, a further form of embodiment may be contemplated as shown in FIGS. 12 and 13, wherein the heel may be released by pulling or raising the control lever. Also in these figures the parts similar to those of the preceding forms of embodiment are designated by the same reference numeral but bearing the index b. This third form of embodiment is so arranged that the spring b of the resilient return mechanism does not act directly upon the transverse rotary shaft 9b coupled to the pair of lateral flanges or branches 7b of the gripping jaw supporting bracket. In fact, in this form of embodiment the spring 10b engages a piston or slide 1217 formed on its upper and lower faces with opposite racks 25, 26 meshing the one with a pinion 27 carried by shaft 9b and the other with another pinion 28 or a curved rack carried by one end of the control lever 22b adapted to release the heel-engaging jaw.

In this respect it may be emphasized that this lever 22b is rotatably mounted on the base member 3b about a fulcrum pin 8b also acting as a pivot pin to the lateral flanges or branches 7b of the gripping jaw supporting bracket.

As in the preceding forms of embodiment, the shaft 9b is coupled with the pair of lateral flanges or branches 7b through a pair of trunnions 18b formed at the ends of this shaft and engaging corresponding apertures 19b formed in said lateral flanges or branches.

The arrangement is such that when the piston 12b is pushed by spring 10b to its extreme position (FIG. 13) the heel gripping jaw is held in its lowermost position to retain the heel on the ski. In case of upward movement of the heel the shaft 9b and pinion 27 are caused to rotate in the direction of the arrow F so as to move the piston 12b in the direction of the arrow F (FIG. 12) and compress the spring 10b while pivoting the control lever 22b in the direction of the arrow F Of course, the gripping jaw may be raised on purpose at any time by pulling the lever 22b upwards or in he counter-clockwise direction as seen in FIG. 13, as shown by the arrow F Obviously, the various forms of embodiment described and illustrated herein are given by way of examples only and should not be construed as limiting the scope of the invention. Thus, for example, the spring of the resilient return mechanism may be caused to actuate the transverse rotary shaft 9, 9a or 9b either directly or through any suitable intermediate member.

On the other hand, the release control lever may be coupled either to the gripping jaw supporting bracket as contemplated in the arrangement shown in FIGS. 1 to 5, or to the transverse rotary shaft 9a (FIGS. 9 to 11), or alternatively to a complementary connecting member provided between the spring of said return mechanism and the transverse rotary shaft, as illustrated in FIGS. 12 and 13.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge readily adapt it for the various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

FIG. 14 illustrates another form of embodiment of the heel holds down device of thisv invention wherein the lever 22c controlling the upward or release movement of the jaw is coupled directly to the jaw supporting bracket 20 by means of complementary toothed segments 25c and 260 formed on these two members.

FIG. 15 illustrates another form of embodiment wherein the lever 22d controlling upward or release movement of the jaw comprises at its front end a roller 33 adapted to engage a cam face 34 formed on the upper portion of the jaw supporting bracket 2d in order to cause same to pivot in the direction of the arrow F, when this lever is raised in the direction of the arrow F-,.

In either case the lever 22c or 22d is normally caused to bear on the top of the corresponding fixed base member 30 or 3d in its lower position. Under these conditions, it is only necessary to pull the rear end of this lever by means of the safety strap 23 for controlling the upward or release movement of the gripping jaw.

What I claim is:

1. Heel hold down device for resiliently and releasably binding the heel of a ski boot to a ski comprising a base member secured to the upper surface of a ski, a heel, gripping jaw, said jaw being pivotally mounted on said base member, a resilient mechanism housed within said base member for controlling the movement of said jaw, said resilient mechanism comprising a transverse rotary shaft, said shaft being rotatable between a predetermined normal position and a second position, spring means for urging said shaft into said predetermined normal position, a trunnion, said trunnion being positioned eccectrically with regard to the axis of said shaft and secured to at least one end of said shaft such that rotation of said shaft moves said trunnion, means for communicating the movement of said trunnion to said jaw, said communicating means having a cam surface formed thereon, said cam surface communicating with said trunnion and having a contour such that when said shaft is in said predetermined normal position said trunnion acts on said communicating means to retain said jaw in the heel holding position and when said shaft is rotated against the force of said spring means to said second position said trunnion acts on said communicating means to permit said jaw to move into the heel releasing position.

2. The device specified in claim 1 wherein said communicating means comprises a bracket pivotally mounted on said base member about an axis transverse to the longitudinal direction of said base member, said bracket including a flange extending in a longitudinal vertical plane, said jaw being secured to said bracket for pivotal movement therewith.

3. The device specified in claim 2 wherein said cam surface is formed on said flange.

4. The device specified in claim 3 wherein said cam surface is formed such that said trunnion causes no return torque on said communicating means when said jaw is in the heel releasing position.

5. The device specified in claim 4 further comprising means for controlling the rotation of said shaft.

6. The device specified in claim 5 wherein said shaft control means comprises a lever rigidly mounted to 

1. Heel hold down device for resiliently and releasably binding the heel of a ski boot to a ski comprising a base member secured to the upper surface of a ski, a heel gripping jaw, said jaw being pivotally mounted on said base member, a resilient mechanism housed within said base member for controlling the movement of said jaw, said resilient mechanism comprising a transverse rotary shaft, said shaft being rotatable between a predetermined normal position and a second position, spring means for urging said shaft into said predetermined normal position, a trunnion, said trunnion being positioned eccectrically with regard to the axis of said shaft and secured to at least one end of said shaft such that rotation of said shaft moves said trunnion, means for communicating the movement of said trunnion to said jaw, said communicating means having a cam surface formed thereon, said cam surface communicating with said trunnion and having a contour such that when said shaft is in said predetermined normal position said trunnion acts on said communicating means to retain said jaw in the heel holding position and when said shaft is rotated against the force of said spring means to said second position said trunnion acts on said communicating Means to permit said jaw to move into the heel releasing position.
 2. The device specified in claim 1 wherein said communicating means comprises a bracket pivotally mounted on said base member about an axis transverse to the longitudinal direction of said base member, said bracket including a flange extending in a longitudinal vertical plane, said jaw being secured to said bracket for pivotal movement therewith.
 3. The device specified in claim 2 wherein said cam surface is formed on said flange.
 4. The device specified in claim 3 wherein said cam surface is formed such that said trunnion causes no return torque on said communicating means when said jaw is in the heel releasing position.
 5. The device specified in claim 4 further comprising means for controlling the rotation of said shaft.
 6. The device specified in claim 5 wherein said shaft control means comprises a lever rigidly mounted to said shaft such that when said lever is substantially parallel to the surface of said ski said shaft is retained in said predetermined normal position and when said lever is moved to a position substantially perpendicular to said ski surface said shaft is in said second position.
 7. The device specified in claim 6 wherein said lever is substantially fork shaped with each of the two branches secured to a different end of said shaft. 